ITHACA, N.Y. -- Despite dramatic losses in wild honeybees and in coloniesmaintained by hobbyist beekeepers, Cornell University apiculturists say thepollination needs of commercial agriculture in the United States are beingmet -- for now -- by commercial beekeepers, although their supplies areprecarious.
"Parasitic mite and mite-related diseases have caused the death of mostwild honeybees, and left the commercial colonies at tremendous risk," saidNicholas W. Calderone, head of the university's Dyce Laboratory for HoneyBee Studies and an assistant professor of entomology in the College ofAgriculture and Life Sciences at Cornell. Calling the Varroa mite "thegreatest threat to beekeeping," Calderone said beekeepers have only oneregistered chemical (Apistan) to control Varroa mites, "and European miteshave already become resistant to that chemical, so we must assume the samething will happen in the U.S."
Roger A. Morse, the recently retired Cornell professor of apiculture whotracked the mites and diseases for 25 years, concurs. "The mites representthe greatest threat to beekeeping since European bees were brought to thiscontinent more than three centuries ago," Morse said. "But if we can getthe results of research to the beekeepers, we can keep the crops growingand the honey flowing.
"It's true that these mite diseases have caused the death of 95 to 98percent of the wild honeybee colonies. And more than half the hobbybeekeepers have lost all or most of their colonies," Morse reported."However, commercial beekeepers in this country are surviving, though they,too, have had serious losses. Research on the biology and control of beediseases is making it possible for the industry to cope and provide the 1.2million colonies needed for the pollination of crops we eat."
Some 90 different crops -- ranging from apples to zucchini and cantaloupesto cucumbers -- depend on honeybee pollination. To some extent, otherinsects will pollinate specific crops. However, no insect is as widelyeffective as the honeybee, and with the disease losses among wild andhobbyist honeybees, the commercial honeybees are more important than ever,Morse observed. The value added by honeybee pollination to Americanagriculture is estimated to range from $5 billion to $20 billion a year, hesaid.
Crop pollination is a migratory enterprise, with honeybees followingseasonal crops -- week by week -- as trees and other plants bloom. Manycommercial beekeepers' bees winter in Florida and travel on trucks thathold up to 500 colonies and 10 million to 15 million pollinators.Commercial beekeepers place their colonies near crops that need pollinatingand charge growers for the service. Migratory beekeepers also sell thehoney and other bee products that result, but fees for pollination servicesare their main source of income.
"We need to sustain a significant research effort to protect the safe andaffordable supply of fruits and vegetables to which people have becomeaccustomed," Calderone said. "Mites are living organisms, and mitepopulations will eventually adapt to whatever control measures we develop.It is an ongoing struggle that can never be completely won."
So research efforts at Cornell and other institutions are focusing on thebiology of the Varroa mite, trying to understand how it locates bees in thefirst place. "If we can determine the host-location mechanism and discoverthe physical and chemical cues the mites use, we may be able to manipulatethose cues for a control mechanism that will protect the bees," Calderonesaid. A number of natural products, including essential oils from herbsand spices, also are being examined for their potential in mite control, headded.
But a genetic solution -- breeding bees that are resistant to mites -- willbe much more difficult, Calderone predicted. Even if beekeepers start withdisease-resistant stock, it is almost impossible to control mating (withnon-resistant males) when new queens leave the colonies, he explained."Commercially viable, disease-resistant stock is the best answer, but thatis years away, at best," Calderone said. 'Nonetheless, it remains thelong-term focus of several research programs around the country."
Meanwhile, commercial beekeepers are surviving by applying good managementtechniques in their craft, Morse said. Dead colonies are replaced whenbeekeepers "split" their surviving colonies each year to maintain thestock needed for pollination.
"Growers who rent bees are well aware of the problems and are making planswith beekeepers for the colonies they will need for next spring'spollination," Morse said. "At the same time, there continues to be a greatinterest in hobby beekeeping, and hobbyists also are learning to cope withmites and diseases by tapping into resources like Cornell's apicultureextension program."
Materials provided by Cornell University. Note: Content may be edited for style and length.
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